On the street, Corey Murray and his One Way crew of teenage cyclists make these large BMX bikes do things most adults wouldn't dare.

Murray is 16, a sophomore at South Philadelphia High School, and life revolves around riding his bike. That's more or less his plan for the future.

His 26-inch "Fat Ripper" retails for just under $850 but SE gave it to him for free. Murray's 78,000-plus Instagram followers have something to do with that.

"I just want to ride and make money riding after high school," Murray said, grinning last week between wheelies down in the Broad Street Line concourse by Locust Street.

On any weekend in Philly and New York City, particularly in the summer, hundreds of teens such as Murray are out in the streets, stunting on bicycles originally designed for dirt motocross tracks. Occasionally, they annoy motorists by swerving close to cars. Sometimes they crash.

Almost all of them are riding SE bicycles.

The SE brand was created in 1977 in Long Beach, Calif., and thrived in the heyday of BMX dirt-track racing. The company created one of the sport's most legendary bikes, the "P.K. Ripper," named after rider Perry Kramer.

Today, SE is one of six brands produced by Advanced Sports International on Dutton Road in Northeast Philadelphia.

Though Advanced Sports has its own marketing department, spokeswoman Larkin Silverman said much of the success for SE's resurgence is due to its brand manager, Todd Lyons, an old-school BMX guy who works out of California.

"SE is Todd's baby and the BMX community looks up to him," Silverman said.

Lyons, 45, said the "Big Rippers" now so popular with teens in Philly and New York were originally designed for guys like himself, former BMX riders now in their 30s and 40s who'd gotten a little too big for the standard 20-inch bike.

SE first made the bigger bikes for a show on MTV in 2008, Lyons said.

"We planned to order 50 and after the show aired, it immediately exploded," he said.

Social media made the brand blow up a few years later, Lyons said, mostly due to one quiet, magical rider in Harlem named Darnell Myers, known as "rrdblocks" on Instagram. Myers was already riding an SE when Lyons saw him on Instagram in 2014 and the company sent him a "Santa Cruz Big Ripper" and started sponsoring him. The Instagram posts went up and Myers' 215,000-plus followers rode right to the bike shop looking for SE.

"I just like riding," Myers said last week. "I been riding since I was 12. Social media has pushed out everything. People see my videos and they do what I do. They see I'm having fun and they want to have fun too."

Lyons said SE is constantly trying to keep up with the movement.

"It's been unexpected," he said. "We haven't been able to keep them in stock and most of our stock is 100 percent presold. We're doubling and tripling what we did last year."

Kenn Rymdeko, cofounder of the Philly Pumptrack at 52nd and Parkside, said there's been a "gigantic rise" in BMX riding in the city and while it's not traditional BMX, he says it's still great to see kids on bikes.

"This is a good thing for everyone," said Rymdeko, 44. "Would I like to see them wearing helmets and not riding in the street? Absolutely."

Down in the Broad Street concourse last week, Murray was doing wheelies and dragging his hand on the ground while a half-dozen teens watched from their bikes.

Harry Murray said the crew has a simple philosophy that keeps them out of serious trouble: you can't ride a bike in jail.

Corey Murray could have been in jail, or the hospital, after swerving too close to an SUV earlier this year — on purpose. A YouTube video titled A Day in the Life of Oneway Corey ends with Murray riding a wheelie and clipping the SUV's front fender, sending him flying over the handlebars and into the street. He got up and ran away with his bike and didn't get caught.

"My back hurt for, like, three months after that, though," he said, smiling.

Murray said his parents would like him to wear a helmet but by law, he doesn't have to.

"They're supportive. They know I love it," he said. "They just said I can't swerve no more."